On Linux, define _GNU_SOURCE so that GNU libc exposes the wcwidth()

[mmh] / configure.in

diff --git a/configure.in b/configure.in
index b66a6e5..e113860 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -221,14 +221,29 @@ fi
 
 AC_PROG_CC
 
+AC_CACHE_CHECK(whether compiler supports -Wno-pointer-sign, nmh_cv_has_noptrsign,
+[nmh_saved_cflags="$CFLAGS"
+ CFLAGS="$CFLAGS -Wno-pointer-sign"
+ AC_TRY_COMPILE([],[],nmh_cv_has_noptrsign=yes,nmh_cv_has_noptrsign=no)
+ CFLAGS="$nmh_saved_cflags"])
+
 dnl if the user hasn't specified CFLAGS, then
 dnl   if compiler is gcc, then
 dnl     use -O2 and some warning flags
 dnl   else use -O
+dnl We use -Wall; if the compiler supports it we also use -Wno-pointer-sign,
+dnl because gcc 4 now produces a lot of new warnings which are probably mostly
+dnl spurious and which in any case we don't want to deal with now.
+if test "$nmh_cv_has_noptrsign" = "yes"; then
+        nmh_gcc_warnflags="-Wall -Wno-pointer-sign"
+else
+        nmh_gcc_warnflags="-Wall"
+fi
+
 if test -n "$auto_cflags"; then
   if test x"$enable_debug" = x"yes"; then
     if test -n "$GCC"; then
-      test -z "$CFLAGS" && CFLAGS="-Wall -g" || CFLAGS="$CFLAGS -Wall -g"
+      test -z "$CFLAGS" && CFLAGS="$nmh_gcc_warnflags -g" || CFLAGS="$CFLAGS $nmh_gcc_warnflags -g"
     else
       test -z "$CFLAGS" && CFLAGS=-g || CFLAGS="$CFLAGS -g"
     fi
@@ -244,7 +259,7 @@ if test -n "$auto_cflags"; then
       esac
     fi
     if test -n "$GCC"; then
-      test -z "$CFLAGS" && CFLAGS="-Wall -O2" || CFLAGS="$CFLAGS -Wall -O2"
+      test -z "$CFLAGS" && CFLAGS="$nmh_gcc_warnflags -O2" || CFLAGS="$CFLAGS $nmh_gcc_warnflags -O2"
     else
       test -z "$CFLAGS" && CFLAGS=-O  || CFLAGS="$CFLAGS -O"
     fi
@@ -367,20 +382,6 @@ if test -z "$editorpath"; then
 fi
 AC_SUBST(editorpath)dnl
 
-dnl Check for broken vi
-AC_CACHE_CHECK(for broken vi, nmh_cv_attvibug,
-[if echo 'r /nonexist-file
-q' | ex > /dev/null
-then
-        nmh_cv_attvibug=no
-else
-        nmh_cv_attvibug=yes
-fi])
- 
-if test "$nmh_cv_attvibug" = yes; then
-  AC_DEFINE(ATTVIBUG)dnl
-fi
-
 dnl ----------------------------------------------------------
 dnl FIND MAIL SPOOL AND SEE IF WE NEED TO MAKE inc SETGID MAIL
 dnl ----------------------------------------------------------
@@ -443,6 +444,25 @@ AC_SUBST(MAIL_SPOOL_GRP)dnl
 dnl ------------------
 dnl CHECK HEADER FILES
 dnl ------------------
+
+dnl On glibc we need to define at least the '_XOPEN_SOURCE' level of features,
+dnl or wchar.h doesn't declare a prototype for wcwidth(). But if we only define
+dnl that level then db.h won't compile. So we define _GNU_SOURCE which turns
+dnl on everything. Perhaps other OSes need some feature switch set to get wcwidth()
+dnl declared; if so they should have an entry added to this case statement.
+dnl NB that we must define this on the compiler command line, not in config.h,
+dnl because it must be set before any system header is included and there's no
+dnl portable way to make sure that files generated by lex include config.h
+dnl before system header files.
+
+case "$target_os" in
+  linux*)
+    # Like DEFS, but doesn't get stomped on by configure when using config.h:
+    OURDEFS="$OURDEFS -D_GNU_SOURCE"
+    ;;
+esac
+AC_SUBST(OURDEFS)
+
 AC_HEADER_DIRENT
 AC_HEADER_STDC
 AC_HEADER_TIME
@@ -983,6 +1003,7 @@ target os                  : ${target}
 compiler                   : ${CC}
 compiler flags             : ${CFLAGS}
 linker flags               : ${LDFLAGS}
+definitions                : ${OURDEFS}
 source code location       : ${srcdir}
 binary install path        : ${nmhbin2}
 libary install path        : ${nmhlib2}